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        <h2>
          <span class="refentrytitle">expon</span>
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        <p>expon — 
      Trace an exponential curve between specified points.
    </p>
      </div>
      <div class="refsect1">
        <a id="idp101686176"></a>
        <h2>Description</h2>
        <p>
      Trace an exponential curve between specified points.
    </p>
      </div>
      <div class="refsect1">
        <a id="idp101687472"></a>
        <h2>Syntax</h2>
        <pre class="synopsis">ares <span class="command"><strong>expon</strong></span> ia, idur, ib</pre>
        <pre class="synopsis">kres <span class="command"><strong>expon</strong></span> ia, idur, ib</pre>
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      <div class="refsect1">
        <a id="idp101691056"></a>
        <h2>Initialization</h2>
        <p>
      <span class="emphasis"><em>ia</em></span> -- starting value. Zero is illegal for exponentials.
    </p>
        <p>
      <span class="emphasis"><em>ib</em></span> -- value after <span class="emphasis"><em>idur</em></span> seconds. For exponentials, must be non-zero and must agree in sign with <span class="emphasis"><em>ia</em></span>.
    </p>
        <p>
      <span class="emphasis"><em>idur</em></span> -- duration in seconds of the segment. A zero or negative value will cause all initialization to be skipped.
    </p>
      </div>
      <div class="refsect1">
        <a id="idp101695616"></a>
        <h2>Performance</h2>
        <p>
      These units generate control or audio signals whose values can pass through 2 specified points. The <span class="emphasis"><em>idur</em></span> value may or may not equal the instrument's performance time: a shorter performance will truncate the specified pattern, while a longer one will cause the defined segment to continue on in the same direction.
    </p>
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      <div class="refsect1">
        <a id="idp101697824"></a>
        <h2>Examples</h2>
        <p>
      Here is an example of the expon opcode. It uses the file <a class="ulink" href="examples/expon.csd" target="_top"><em class="citetitle">expon.csd</em></a>.

      </p>
        <div class="example">
          <a id="idp101699600"></a>
          <p class="title">
            <strong>Example 235. Example of the expon opcode.</strong>
          </p>
          <div class="example-contents">
            <p>See the sections <a class="link" href="UsingRealTime.html" title="Real-Time Audio"><em class="citetitle">Real-time Audio</em></a> and <a class="link" href="CommandFlags.html" title="Csound command line"><em class="citetitle">Command Line Flags</em></a> for more information on using command line flags.</p>
            <pre class="programlisting">
<span class="csdtag">&lt;CsoundSynthesizer&gt;</span>
<span class="csdtag">&lt;CsOptions&gt;</span>
<span class="comment">; Select audio/midi flags here according to platform</span>
-odac     <span class="comment">;;;realtime audio out</span>
<span class="comment">;-iadc    ;;;uncomment -iadc if realtime audio input is needed too</span>
<span class="comment">; For Non-realtime ouput leave only the line below:</span>
<span class="comment">; -o expon.wav -W ;;; for file output any platform</span>
<span class="csdtag">&lt;/CsOptions&gt;</span>
<span class="csdtag">&lt;CsInstruments&gt;</span>

<span class="ohdr">sr</span> <span class="op">=</span> 44100
<span class="ohdr">ksmps</span> <span class="op">=</span> 32
<span class="ohdr">nchnls</span> <span class="op">=</span> 2
<span class="ohdr">0dbfs</span> <span class="op">=</span> 1

<span class="oblock">instr</span> 1 

kpitch <span class="op">=</span> p6
<span class="comment">;choose between expon or line</span>
<span class="octrl">if</span> (kpitch <span class="op">==</span> 0) then 	
  kpitch <span class="opc">expon</span> p4, p3, p5 
<span class="octrl">elseif</span> (kpitch <span class="op">==</span> 1) then
  kpitch <span class="opc">line</span> p4, p3, p5 
<span class="octrl">endif</span>

asig   <span class="opc">vco2</span> .6, kpitch 
       <span class="opc">outs</span> asig, asig

<span class="oblock">endin</span> 
<span class="csdtag">&lt;/CsInstruments&gt;</span>
<span class="csdtag">&lt;CsScore&gt;</span>
 

<span class="stamnt">i</span> 1 0 2 300 600    0	<span class="comment">;if p6=0 then expon is used</span>
<span class="stamnt">i</span> 1 3 2 300 600    1	<span class="comment">;if p6=1 then line is used</span>
<span class="stamnt">i</span> 1 6 2 600 1200   0
<span class="stamnt">i</span> 1 9 2 600 1200   1
<span class="stamnt">i</span> 1 12 2 1200 2400 0
<span class="stamnt">i</span> 1 15 2 1200 2400 1
<span class="stamnt">i</span> 1 18 2 2400 30   0
<span class="stamnt">i</span> 1 21 2 2400 30   1
<span class="stamnt">e</span>
<span class="csdtag">&lt;/CsScore&gt;</span>
<span class="csdtag">&lt;/CsoundSynthesizer&gt;</span>
</pre>
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        <p><br class="example-break" />
    </p>
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        <a id="idp101703888"></a>
        <h2>See Also</h2>
        <p>
      <a class="link" href="expseg.html" title="expseg"><em class="citetitle">expseg</em></a>,
      <a class="link" href="expsegr.html" title="expsegr"><em class="citetitle">expsegr</em></a>,
      <a class="link" href="line.html" title="line"><em class="citetitle">line</em></a>,
      <a class="link" href="linseg.html" title="linseg"><em class="citetitle">linseg</em></a>,
      <a class="link" href="linsegr.html" title="linsegr"><em class="citetitle">linsegr</em></a>
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